Nanowired ultra-capacitor based power sources for implantable sensors and devices

Abstract

Various examples related to power sources for implantable sensors and/or devices are provided. In one example, a device for implantation in a subject includes circuitry for sensing an observable parameter of the subject and a power source comprising a nanowired ultra-capacitor (NUC), the power source having a volume of 10 mm 3 or less. The NUC can have a surface capacitance density in a range from about 25 mF/cm 2 to about 29 mF/cm 2 or greater. Such devices can be used for, e.g., ocular diagnostic sensors or other implantable sensors that may be constrained by size limitations.

The invention claimed is: 
     
       1. A device for implantation in a subject, comprising:
 circuitry for sensing presence and duration of an observable parameter of the subject; and 
 a power source comprising a nanowired ultra-capacitor (NUC) having a negligible intrinsic self-discharge rate of 2 nA or less and a high self-discharge resistance of 250 MΩ or more, the power source configured to provide electrical power to the circuitry for sensing the observable parameter, where the presence and duration of the observable parameter are based upon sensed changes in discharge rate of the NUC. 
 
     
     
       2. The device of  claim 1 , wherein the observable parameter is intraocular pressure (IOP). 
     
     
       3. The device of  claim 1 , wherein the circuitry comprises a pressure sensitive microswitch. 
     
     
       4. The device of  claim 1 , wherein the power source has a volume of 10 mm 3  or less. 
     
     
       5. The device of  claim 1 , wherein the volume of the power source is 5 mm 3  or less. 
     
     
       6. The device of  claim 1 , wherein the volume of the power source is 2 mm 3  or less. 
     
     
       7. The device of  claim 1 , wherein the power source comprises a plurality of NUCs coupled in parallel. 
     
     
       8. The device of  claim 7 , wherein the plurality of NUCs are stacked. 
     
     
       9. The device of  claim 7 , wherein the plurality of NUCs are adjacent to each other. 
     
     
       10. The device of  claim 7 , wherein the plurality of NUCs are disjointly distributed in a common plane or in different planes. 
     
     
       11. The device of  claim 7 , wherein the plurality of NUCs are disjointly distributed in different locations. 
     
     
       12. The device of  claim 7 , wherein the plurality of NUCs have a total capacitance that is approximately proportional to the number of NUCs. 
     
     
       13. The device of  claim 1 , wherein the NUC has a surface capacitance density in a range from about 25 mF/cm 2  to about 29 mF/cm 2  or greater. 
     
     
       14. The device of  claim 1 , wherein the device is an ocular diagnostic device. 
     
     
       15. The device of  claim 1 , wherein the circuitry senses intraocular pressure (IOP). 
     
     
       16. The device of  claim 1 , wherein the subject is a human being. 
     
     
       17. The device of  claim 1 , wherein the subject is an animal. 
     
     
       18. The device of  claim 1 , wherein the circuitry for sensing the observable parameter and the power source comprising the NUC are implanted in the subject, the power source electrically coupled to the circuitry for sensing the observable parameter. 
     
     
       19. The device of  claim 18 , wherein the power source is charged via an implanted solar cell. 
     
     
       20. The device of  claim 18 , wherein the power source comprises a plurality of NUCs disjointly distributed in a common location or in different locations in the subject.